organic compounds
2-(4-Chlorobenzoylmethyl)-2H-1,4-benzothiazin-3(4H)-one
aCollege of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050016, People's Republic of China, and bDepartment of Chemical Engineering, Shijiazhuang Vocational Technology Institute, Shijiazhuang 050081, People's Republic of China
*Correspondence e-mail: yuanli@mail.hebtu.edu.cn
The six-membered heterocyclic ring in the title compound, C16H12ClNO2S, exists in a conformation intermediate between twist-boat and chair. A one-dimensional chain structure is formed as a result of intermolecular N—H⋯O and C—H⋯O hydrogen bonds via crystallographic inversion symmetry and translation along the a axis.
Related literature
For the synthesis and biological activities of related et al. (2005); Pant et al. (2006). For microwave-assisted syntheses of related compounds, see: Dandia et al. (2002). For further related literature, see: Pant & Chugh (1989); Kirchner & Alexander (1959); Beryozkina et al. (2004); Pant et al. (1987).
and 1,5-benzothiazepines, see: AnsariExperimental
Crystal data
|
Refinement
|
Data collection: APEX2 (Bruker, 1997); cell SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).
Supporting information
10.1107/S1600536808007423/si2076sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808007423/si2076Isup2.hkl
4-(4-chlorophenyl)-4-oxo-2-butenoic acid was prepared by AlCl3 catalysed treatment of powdered meleic anhydride with chlorobenzene following the general literature procedure. (Pant et al., 1987). 2-Aminothiophenol (2 mmol) and 4-(4-chlorophenyl)-4-oxo-2-butenoic acid (2 mmol) were refluxed with dry ethanol saturated with hydrogen chloride gas. Excess of solvent was concentrated by distillation under reduced pressure and the residue crystallized from methanol to give the title compound as light yellow crystals suitable for X-ray
Analysis calculated for C16H12ClNO2S: C 60.47, H 3.81, N 4.41%; found: C 60.45, H 3.80, N 4.40%.All H atoms were placed in calculated positions and constrained to ride on their parent atoms, with C—H distances of 0.93 Å (aryl C) and 0.97–0.98 Å (Csp3), and N—H distance of 0.86 Å, with all Uiso(H) = 1.2Ueq(Csp2).
Data collection: APEX2 (Bruker, 1997); cell
SAINT (Bruker, 1997); data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).Fig. 1. Molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. |
C16H12ClNO2S | Z = 2 |
Mr = 317.78 | F(000) = 328 |
Triclinic, P1 | Dx = 1.446 Mg m−3 |
a = 7.7273 (19) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 8.649 (2) Å | Cell parameters from 2700 reflections |
c = 12.298 (3) Å | θ = 2.5–28.0° |
α = 82.032 (3)° | µ = 0.41 mm−1 |
β = 72.349 (2)° | T = 273 K |
γ = 68.829 (3)° | Labellar, colorless |
V = 730.0 (3) Å3 | 0.24 × 0.20 × 0.18 mm |
Bruker APEXII CCD area-detector diffractometer | 2545 independent reflections |
Radiation source: fine-focus sealed tube | 2236 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.009 |
ϕ and ω scans | θmax = 25.0°, θmin = 1.7° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) | h = −9→9 |
Tmin = 0.876, Tmax = 1.000 | k = −10→8 |
3962 measured reflections | l = −14→14 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.030 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.082 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0412P)2 + 0.2045P] where P = (Fo2 + 2Fc2)/3 |
2545 reflections | (Δ/σ)max < 0.001 |
190 parameters | Δρmax = 0.18 e Å−3 |
0 restraints | Δρmin = −0.27 e Å−3 |
C16H12ClNO2S | γ = 68.829 (3)° |
Mr = 317.78 | V = 730.0 (3) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.7273 (19) Å | Mo Kα radiation |
b = 8.649 (2) Å | µ = 0.41 mm−1 |
c = 12.298 (3) Å | T = 273 K |
α = 82.032 (3)° | 0.24 × 0.20 × 0.18 mm |
β = 72.349 (2)° |
Bruker APEXII CCD area-detector diffractometer | 2545 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) | 2236 reflections with I > 2σ(I) |
Tmin = 0.876, Tmax = 1.000 | Rint = 0.009 |
3962 measured reflections |
R[F2 > 2σ(F2)] = 0.030 | 0 restraints |
wR(F2) = 0.082 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.18 e Å−3 |
2545 reflections | Δρmin = −0.27 e Å−3 |
190 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
Cl1 | −0.60724 (7) | 0.61069 (8) | 0.87177 (5) | 0.0776 (2) | |
S1 | 0.31357 (6) | 0.84225 (6) | 0.23145 (3) | 0.04914 (15) | |
O1 | 0.30018 (15) | 0.92709 (13) | 0.52142 (9) | 0.0402 (3) | |
O2 | 0.28795 (16) | 0.57700 (15) | 0.57928 (11) | 0.0527 (3) | |
N1 | 0.54966 (17) | 0.90262 (15) | 0.36402 (11) | 0.0373 (3) | |
H1 | 0.5980 | 0.9498 | 0.3985 | 0.045* | |
C1 | 0.6460 (2) | 0.86774 (18) | 0.24884 (13) | 0.0363 (3) | |
C2 | 0.8326 (2) | 0.8708 (2) | 0.20508 (15) | 0.0474 (4) | |
H2 | 0.8953 | 0.8892 | 0.2532 | 0.057* | |
C3 | 0.9255 (3) | 0.8467 (2) | 0.09073 (16) | 0.0567 (5) | |
H3 | 1.0508 | 0.8488 | 0.0619 | 0.068* | |
C4 | 0.8333 (3) | 0.8197 (3) | 0.01912 (16) | 0.0632 (5) | |
H4 | 0.8959 | 0.8043 | −0.0582 | 0.076* | |
C5 | 0.6482 (3) | 0.8155 (3) | 0.06182 (15) | 0.0571 (5) | |
H5 | 0.5869 | 0.7963 | 0.0132 | 0.069* | |
C6 | 0.5527 (2) | 0.8397 (2) | 0.17663 (13) | 0.0418 (4) | |
C7 | 0.3290 (2) | 0.75703 (18) | 0.37328 (12) | 0.0344 (3) | |
H7 | 0.4274 | 0.6463 | 0.3666 | 0.041* | |
C8 | 0.3893 (2) | 0.87005 (17) | 0.42642 (12) | 0.0327 (3) | |
C9 | 0.1349 (2) | 0.74330 (18) | 0.44118 (12) | 0.0353 (3) | |
H9A | 0.0417 | 0.8540 | 0.4564 | 0.042* | |
H9B | 0.0918 | 0.6900 | 0.3952 | 0.042* | |
C10 | 0.1384 (2) | 0.64667 (18) | 0.55313 (13) | 0.0361 (3) | |
C11 | −0.0490 (2) | 0.63785 (17) | 0.63063 (13) | 0.0348 (3) | |
C12 | −0.2165 (2) | 0.68862 (19) | 0.59542 (14) | 0.0399 (4) | |
H12 | −0.2133 | 0.7301 | 0.5212 | 0.048* | |
C13 | −0.3878 (2) | 0.6784 (2) | 0.66903 (15) | 0.0448 (4) | |
H13 | −0.4992 | 0.7119 | 0.6448 | 0.054* | |
C14 | −0.3901 (2) | 0.6180 (2) | 0.77841 (15) | 0.0457 (4) | |
C15 | −0.2254 (3) | 0.5640 (2) | 0.81540 (15) | 0.0537 (4) | |
H15 | −0.2293 | 0.5219 | 0.8896 | 0.064* | |
C16 | −0.0555 (2) | 0.5732 (2) | 0.74112 (14) | 0.0467 (4) | |
H16 | 0.0563 | 0.5357 | 0.7652 | 0.056* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0481 (3) | 0.1072 (5) | 0.0628 (3) | −0.0307 (3) | 0.0052 (2) | 0.0103 (3) |
S1 | 0.0396 (2) | 0.0791 (3) | 0.0395 (2) | −0.0307 (2) | −0.01448 (18) | 0.0016 (2) |
O1 | 0.0368 (6) | 0.0468 (6) | 0.0402 (6) | −0.0183 (5) | −0.0069 (5) | −0.0085 (5) |
O2 | 0.0335 (6) | 0.0611 (7) | 0.0604 (8) | −0.0122 (5) | −0.0183 (5) | 0.0097 (6) |
N1 | 0.0339 (7) | 0.0453 (7) | 0.0402 (7) | −0.0202 (6) | −0.0103 (5) | −0.0062 (5) |
C1 | 0.0336 (8) | 0.0368 (8) | 0.0399 (8) | −0.0150 (6) | −0.0090 (6) | 0.0000 (6) |
C2 | 0.0380 (9) | 0.0573 (10) | 0.0510 (10) | −0.0223 (8) | −0.0117 (7) | 0.0011 (8) |
C3 | 0.0409 (10) | 0.0716 (12) | 0.0548 (11) | −0.0273 (9) | −0.0001 (8) | 0.0001 (9) |
C4 | 0.0591 (12) | 0.0848 (14) | 0.0433 (10) | −0.0350 (11) | 0.0042 (9) | −0.0065 (9) |
C5 | 0.0593 (11) | 0.0816 (13) | 0.0404 (9) | −0.0376 (10) | −0.0095 (8) | −0.0051 (9) |
C6 | 0.0378 (9) | 0.0499 (9) | 0.0403 (8) | −0.0205 (7) | −0.0080 (7) | −0.0003 (7) |
C7 | 0.0299 (7) | 0.0368 (8) | 0.0389 (8) | −0.0132 (6) | −0.0095 (6) | −0.0036 (6) |
C8 | 0.0284 (7) | 0.0329 (7) | 0.0381 (8) | −0.0099 (6) | −0.0121 (6) | 0.0000 (6) |
C9 | 0.0298 (8) | 0.0371 (8) | 0.0427 (8) | −0.0144 (6) | −0.0107 (6) | −0.0032 (6) |
C10 | 0.0326 (8) | 0.0345 (8) | 0.0436 (8) | −0.0118 (6) | −0.0120 (6) | −0.0040 (6) |
C11 | 0.0341 (8) | 0.0318 (7) | 0.0404 (8) | −0.0122 (6) | −0.0110 (6) | −0.0025 (6) |
C12 | 0.0373 (8) | 0.0420 (8) | 0.0427 (8) | −0.0169 (7) | −0.0141 (7) | 0.0078 (7) |
C13 | 0.0346 (8) | 0.0471 (9) | 0.0542 (10) | −0.0166 (7) | −0.0147 (7) | 0.0070 (7) |
C14 | 0.0375 (9) | 0.0491 (9) | 0.0457 (9) | −0.0161 (7) | −0.0025 (7) | −0.0021 (7) |
C15 | 0.0521 (11) | 0.0704 (12) | 0.0363 (9) | −0.0216 (9) | −0.0106 (8) | 0.0047 (8) |
C16 | 0.0418 (9) | 0.0573 (10) | 0.0431 (9) | −0.0155 (8) | −0.0170 (7) | 0.0002 (7) |
Cl1—C14 | 1.7394 (17) | C7—C8 | 1.5135 (19) |
S1—C6 | 1.7573 (16) | C7—C9 | 1.5173 (19) |
S1—C7 | 1.8182 (15) | C7—H7 | 0.9800 |
O1—C8 | 1.2284 (18) | C9—C10 | 1.511 (2) |
O2—C10 | 1.2129 (18) | C9—H9A | 0.9700 |
N1—C8 | 1.3489 (18) | C9—H9B | 0.9700 |
N1—C1 | 1.403 (2) | C10—C11 | 1.494 (2) |
N1—H1 | 0.8600 | C11—C16 | 1.389 (2) |
C1—C2 | 1.386 (2) | C11—C12 | 1.390 (2) |
C1—C6 | 1.394 (2) | C12—C13 | 1.384 (2) |
C2—C3 | 1.377 (2) | C12—H12 | 0.9300 |
C2—H2 | 0.9300 | C13—C14 | 1.371 (2) |
C3—C4 | 1.377 (3) | C13—H13 | 0.9300 |
C3—H3 | 0.9300 | C14—C15 | 1.381 (3) |
C4—C5 | 1.378 (3) | C15—C16 | 1.376 (2) |
C4—H4 | 0.9300 | C15—H15 | 0.9300 |
C5—C6 | 1.386 (2) | C16—H16 | 0.9300 |
C5—H5 | 0.9300 | ||
C6—S1—C7 | 97.48 (7) | O1—C8—C7 | 122.41 (13) |
C8—N1—C1 | 126.91 (12) | N1—C8—C7 | 116.00 (12) |
C8—N1—H1 | 116.5 | C10—C9—C7 | 113.70 (12) |
C1—N1—H1 | 116.5 | C10—C9—H9A | 108.8 |
C2—C1—C6 | 119.70 (14) | C7—C9—H9A | 108.8 |
C2—C1—N1 | 119.38 (14) | C10—C9—H9B | 108.8 |
C6—C1—N1 | 120.82 (13) | C7—C9—H9B | 108.8 |
C3—C2—C1 | 120.31 (16) | H9A—C9—H9B | 107.7 |
C3—C2—H2 | 119.8 | O2—C10—C11 | 120.79 (14) |
C1—C2—H2 | 119.8 | O2—C10—C9 | 121.44 (14) |
C4—C3—C2 | 120.09 (16) | C11—C10—C9 | 117.77 (12) |
C4—C3—H3 | 120.0 | C16—C11—C12 | 118.65 (14) |
C2—C3—H3 | 120.0 | C16—C11—C10 | 118.96 (13) |
C3—C4—C5 | 120.09 (17) | C12—C11—C10 | 122.38 (14) |
C3—C4—H4 | 120.0 | C13—C12—C11 | 121.08 (15) |
C5—C4—H4 | 120.0 | C13—C12—H12 | 119.5 |
C4—C5—C6 | 120.49 (17) | C11—C12—H12 | 119.5 |
C4—C5—H5 | 119.8 | C14—C13—C12 | 118.69 (15) |
C6—C5—H5 | 119.8 | C14—C13—H13 | 120.7 |
C5—C6—C1 | 119.31 (15) | C12—C13—H13 | 120.7 |
C5—C6—S1 | 121.07 (13) | C13—C14—C15 | 121.61 (15) |
C1—C6—S1 | 119.58 (12) | C13—C14—Cl1 | 118.54 (13) |
C8—C7—C9 | 112.96 (12) | C15—C14—Cl1 | 119.85 (14) |
C8—C7—S1 | 107.61 (10) | C16—C15—C14 | 119.17 (16) |
C9—C7—S1 | 108.66 (10) | C16—C15—H15 | 120.4 |
C8—C7—H7 | 109.2 | C14—C15—H15 | 120.4 |
C9—C7—H7 | 109.2 | C15—C16—C11 | 120.77 (15) |
S1—C7—H7 | 109.2 | C15—C16—H16 | 119.6 |
O1—C8—N1 | 121.58 (13) | C11—C16—H16 | 119.6 |
C8—N1—C1—C2 | −164.11 (15) | C9—C7—C8—N1 | −172.83 (12) |
C8—N1—C1—C6 | 19.6 (2) | S1—C7—C8—N1 | −52.90 (15) |
C6—C1—C2—C3 | 0.2 (3) | C8—C7—C9—C10 | −70.81 (16) |
N1—C1—C2—C3 | −176.10 (16) | S1—C7—C9—C10 | 169.86 (10) |
C1—C2—C3—C4 | 0.1 (3) | C7—C9—C10—O2 | −5.5 (2) |
C2—C3—C4—C5 | −0.5 (3) | C7—C9—C10—C11 | 175.14 (12) |
C3—C4—C5—C6 | 0.5 (3) | O2—C10—C11—C16 | 10.8 (2) |
C4—C5—C6—C1 | −0.2 (3) | C9—C10—C11—C16 | −169.83 (14) |
C4—C5—C6—S1 | 177.63 (15) | O2—C10—C11—C12 | −167.67 (15) |
C2—C1—C6—C5 | −0.1 (2) | C9—C10—C11—C12 | 11.7 (2) |
N1—C1—C6—C5 | 176.12 (15) | C16—C11—C12—C13 | 1.3 (2) |
C2—C1—C6—S1 | −178.03 (12) | C10—C11—C12—C13 | 179.77 (14) |
N1—C1—C6—S1 | −1.8 (2) | C11—C12—C13—C14 | 0.4 (2) |
C7—S1—C6—C5 | 148.48 (15) | C12—C13—C14—C15 | −1.5 (3) |
C7—S1—C6—C1 | −33.66 (14) | C12—C13—C14—Cl1 | 178.29 (12) |
C6—S1—C7—C8 | 58.07 (11) | C13—C14—C15—C16 | 0.9 (3) |
C6—S1—C7—C9 | −179.31 (10) | Cl1—C14—C15—C16 | −178.92 (14) |
C1—N1—C8—O1 | −169.12 (14) | C14—C15—C16—C11 | 0.8 (3) |
C1—N1—C8—C7 | 12.0 (2) | C12—C11—C16—C15 | −1.9 (2) |
C9—C7—C8—O1 | 8.3 (2) | C10—C11—C16—C15 | 179.53 (15) |
S1—C7—C8—O1 | 128.25 (13) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1i | 0.86 | 2.02 | 2.8812 (19) | 177 |
C7—H7···O2ii | 0.98 | 2.54 | 3.443 (2) | 152 |
C9—H9A···O1iii | 0.97 | 2.59 | 3.485 (2) | 153 |
C13—H13···O1iv | 0.93 | 2.59 | 3.400 (2) | 145 |
Symmetry codes: (i) −x+1, −y+2, −z+1; (ii) −x+1, −y+1, −z+1; (iii) −x, −y+2, −z+1; (iv) x−1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C16H12ClNO2S |
Mr | 317.78 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 273 |
a, b, c (Å) | 7.7273 (19), 8.649 (2), 12.298 (3) |
α, β, γ (°) | 82.032 (3), 72.349 (2), 68.829 (3) |
V (Å3) | 730.0 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.41 |
Crystal size (mm) | 0.24 × 0.20 × 0.18 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1997) |
Tmin, Tmax | 0.876, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3962, 2545, 2236 |
Rint | 0.009 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.082, 1.06 |
No. of reflections | 2545 |
No. of parameters | 190 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.18, −0.27 |
Computer programs: APEX2 (Bruker, 1997), SAINT (Bruker, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1i | 0.86 | 2.02 | 2.8812 (19) | 177 |
C7—H7···O2ii | 0.98 | 2.54 | 3.443 (2) | 152 |
C9—H9A···O1iii | 0.97 | 2.59 | 3.485 (2) | 153 |
C13—H13···O1iv | 0.93 | 2.59 | 3.400 (2) | 145 |
Symmetry codes: (i) −x+1, −y+2, −z+1; (ii) −x+1, −y+1, −z+1; (iii) −x, −y+2, −z+1; (iv) x−1, y, z. |
Acknowledgements
This work was supported by the Natural Science Foundation of Hebei Province (No. B2007000239), People's Republic of China.
References
Ansari, F. L., Umbreen, S., Hussain, L., Makhmoor, T., Nawaz, S. A., Lodhi, M. A., Khan, S. N., Shaheen, F., Choudhary, M. I. & Atta, U. R. (2005). Chem. Biodivers., 2, 487–496. Web of Science CrossRef PubMed CAS Google Scholar
Beryozkina, T. V., Kolos, N. N., Orlov, V. D., Zubatyuk, R. I. & Shishkin, O. V. (2004). Phosphorus Sulfur Silicon, 179, 2153–2162. Web of Science CSD CrossRef CAS Google Scholar
Bruker (1997). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Dandia, A., Sati, M. & Loupy, A. (2002). Green Chem. 4, 599–602. Web of Science CrossRef CAS Google Scholar
Kirchner, F. K. & Alexander, E. J. (1959). J. Am. Chem. Soc. 81, 1721–1726. CrossRef CAS Web of Science Google Scholar
Pant, S., Chandra, H., Sharma, P. & Pant, U. C. (2006). Indian J. Chem. Sect. B, 45, 1525–1530. Google Scholar
Pant, U. C. & Chugh, M. (1989). Indian J. Chem. Sect. B, 28, 435–436. Google Scholar
Pant, U. C., Gaur, B. S. & Chugh, M. (1987). Indian J. Chem. Sect. B, 26, 947–950. Google Scholar
Sheldrick, G. M. (1997). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
1,5-Benzothiazepine and its derivatives are an important class of bioactive molecules in the field of drugs and pharmaceuticals (Ansari et al., 2005; Pant et al., 2006). The reaction of 2-aminothiophenol with various α,β-unsaturated carbonyl compounds lead to the formation of 1,5-benzothiazepines. We have synthesized some 3-acetyl and 3-alkoxycarbonyl substituted 1,5-benzothiazepines, showing very good activity against fungus candida albicans by the reaction of 2-aminothiophenol with acetylacetone and ethyl acetoacetate. In continuation of our ongoing studies on the synthesis of 4-aryl-2-carboxy-2,3-dihydro-1,5-benzothiazepines for various biological activities, we reacted 2-aminothiophenol with β-aroylacrylic acids, but the formation of a seven-membered ring did not occur. Several authors have reported about the 4-aryl-2-carboxy-2,3-dihydro-1,5-benzothiazepine structure for the products of the reaction of 2-aminothiophenol with β-aroylacrylic acids (Pant & Chugh, 1989; Dandia et al., 2002), and others proposed the formation of 1,4-benzothiazin-3-ones (Kirchner & Alexander, 1959; Beryozkina et al., 2004).
So we repeated the experiment for several times and recrystallized the final product again. Upon X-ray diffraction analysis, along with the spectroscopic data we know that 1,4-benzothiazin-3-one was obtained as the only product (Fig. 1). In the crystalline state, the title compound form a one-dimensional chain structure due to intermolecular N—H···O and C—H···O hydrogen bonds via crystallographic inversion symmetry and translation along the a axis (Table 1). The substituent at atom C7 is equatorially oriented with a torsion angle O1–C8–C7–C9 = 8.3 (2)°. The carbonyl group is slightly turned relative to the chlorophenyl substituent with a torsion angle O2–C10–C11–C16 = 10.8 (2)°. The six-membered heterocycle in the title compound exists in intermediate conformation between twisted boat and chair type.